Reactive oxygen species in TNFalpha-induced signaling and cell death

RIPK1 inhibitor ameliorates pulmonary injury by modulating the function of neutrophils and vascular endothelial cells

Acute lung injury (ALI) is an acute and progressive hypoxic respiratory failure that could progress to acute respiratory distress syndrome (ARDS) with a high mortality rate, thus immediate medical attention and supportive care are necessary. The pathophysiology of ALI is characterized by the disruption of the alveolar-capillary barrier and activation of neutrophils, leading to lung tissue damage. The receptor-interacting protein kinase 1 (RIPK1) has emerged as a promising target for the treatment of multiple inflammatory diseases, but the role of RIPK1 in the ALI remains poorly understood. In this study, we aimed to figure out the pathological role of RIPK1 in ALI, especially in the pulmonary immune microenvironment involving neutrophils and endothelial cells. In vivo experiments showed that RIPK1 inhibitor protected against lipopolysaccharide (LPS)-induced lung injury in mouse models, with reduced neutrophils and monocytes infiltration in the lungs. Further studies demonstrated that, besides the inhibitory action on necroptosis, RIPK1 inhibitor directly suppressed reactive oxygen species (ROS) generation and inflammatory cytokines secretion from neutrophils. Furthermore, RIPK1 inhibition maintains the barrier function in TNF-α-primed vascular endothelial cells and prevents their activation induced by the supernatant from LPS-stimulated neutrophils. Mechanistically, the aforementioned effects of RIPK1 inhibitor are associated with the NF-κB signaling pathway, which is partially independent of necroptosis inhibition. These results provide new evidence that RIPK1 inhibitor directly regulates the function of neutrophils and endothelial cells, as well as interferes with the interactions between these two cell types, therefore contributing to a better understanding of RIPK1 in ALI and providing a potential avenue for future therapeutic interventions.

Study on the combined toxicity of DEHP and lead on the blood system of rats

Di(2-ethylhexyl) phthalate (DEHP) is a commonly used phthalate ester compound, while lead is a persistent and bioaccumulative heavy metal. Both can be exposed to the body through a variety of ways, which may have an impact on the blood system. In this study, we examined the impact of co-exposure to DEHP (0, 10, 100 mg/kg) and Pb (0, 5, 50 mg/kg) on the blood system of male SD rats. The study revealed that continuous exposure to DEHP and Pb for 20 days resulted in a decrease in leukocytes and lymphocytes, while an increase in neutrophils and monocytes. Co-exposure led to a significant decrease in the spleen coefficients. Furthermore, the combined exposure could increase the ratio of bone marrow cells in G1 phase, and decrease the ratio of cells in S phase and G2 phase. Cytokine testing showed that combined exposure affects the secretion of hematopoietic factors and may cause bone marrow cell apoptosis. Single or combined exposure to DEHP and Pb can cause oxidative stress in serum and bone marrow. Overall, these results indicate that the co-exposure of DEHP and Pb adversely affected the blood system of rats, mainly due to the induction of oxidative stress and ultimately affects the secretion of cytokines. The combined effect of the two substances is primarily antagonistic. These results have important implications for the risk assessment of combined pollution and provide valuable theoretical guidance.

pH-responsive resveratrol-loaded ZIF-8 nanoparticles modified with tannic acid for promoting colon cancer cell apoptosis

Resveratrol (Res) is known for its potential in treating various types of cancers, with a particular advantage of causing minimal toxic side effects. However, its clinical application is constrained by challenges such as poor bioavailability, low water solubility, and chemical instability in neutral and alkaline environments. In light of these limitations, we have developed a pH-responsive drug delivery nanoplatform, Res@ZIF-8/TA NPs, which exhibits good biocompatibility and shows promise for in vitro cancer therapy. Benefiting from the mild reaction conditions provided by zeolitic imidazolate frameworks (ZIFs), a "one-pot method" was used for drug synthesis and loading, resulting in a satisfactory loading capacity. Notably, Res@ZIF-8/TA NPs respond to acidic environments, leading to an improved drug release profile with a controlled release effect. Our cell-based experiments indicated that tannic acid (TA) modification enhances the biocompatibility of ZIFs. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT assay), Hoechst 33342/PI staining, cell scratch assay, Transwell and Reverse Transcription quantitative PCR (RT-qPCR) assays further demonstrated that Res@ZIF-8/TA NPs inhibited colon cancer cell migration and invasion, and promoted apoptosis of colon cancer cells, suggesting a therapeutic potential and demonstrating anti-cancer properties. In conclusion, the Res@ZIF-8/TA NPs pH-responsive drug delivery systems we developed may offer a promising avenue for cancer therapy. By addressing some of the challenges associated with Res-based treatments, this system could contribute to advancements in cancer therapeutics.

The cyclin-dependent kinase inhibitor abemaciclib-induced hepatotoxicity: Insight on the molecular mechanisms in HepG2/THP-1 co-culture model

Drug-induced liver injury (DILI) is one of the widespread causes of liver injury and immune system plays important role. Abemaciclib (ABE) is a cyclin-dependent kinase inhibitor used as monotherapy or combination therapy in the treatment of breast cancer. Like other kinase inhibitors, the underlying mechanisms of ABE-induced hepatotoxicity are not completely known yet. In the current study, hepatotoxicity of ABE was evaluated with HepG2/THP-1 co-culture model which has been developed in recent years for the evaluation of DILI potential. Following ABE treatment, oxidative stress, mitochondrial damage, cytokine secretion levels, apoptotic/necrotic cell death were determined. According to our results, ROS production along with GSH depletion was observed in HepG2 cells after ABE treatment. ABE promoted secretion of pro-inflammatory mediators (TNF-α and MCP-1) and declined anti-inflammatory cytokine IL-10 release. Besides, NFKβ and JNK1 protein expression levels increased following ABE treatment. ABE enhanced intracellular calcium levels, induced early apoptotic and necrotic cell deaths in HepG2 cells. Furthermore, the changes in some mitochondrial parameters including a reducement in intracellular ATP levels and complex V activity; hyperpolarized mitochondrial membrane potential and enhanced mitochondrial ROS levels were observed, whereas mitochondrial mass did not show any differences after ABE treatments. Therefore, ABE-induced hepatotoxic effects is probably via oxidative stress, inflammatory response and necrotic cell death rather than direct mitochondrial toxicity. In conclusion; the study makes a significant contribution to strengthening the infrastructure we have on in vitro toxicity mechanism evaluations, which are the basis of preclinical toxicity studies.

Physicochemical Characterization and Immunomodulatory Activity of Polyelectrolyte Multilayer Coatings Incorporating an Exopolysaccharide from Bifidobacterium longum

Immunoregulatory polysaccharides from probiotic bacteria have potential in biomedical engineering. Here, a negatively charged exopolysaccharide from Bifidobacterium longum with confirmed immunoregulatory activity (EPS624) was applied in multilayered polyelectrolyte coatings with positively charged chitosan. EPS624 and coatings (1, 5, and 10 layers and alginate-substituted) were characterized by the zeta potential, dynamic light scattering, size exclusion chromatography, scanning electron microscopy, and atomic force microscopy. Peripheral blood mononuclear cells (hPBMCs) and fibroblasts were exposed for 1, 3, 7, and 10 days with cytokine secretion, viability, and morphology as observations. The coatings showed an increased rugosity and exponential growth mode with an increasing number of layers. A dose/layer-dependent IL-10 response was observed in hPBMCs, which was greater than EPS624 in solution and was stable over 7 days. Fibroblast culture revealed no toxicity or metabolic change after exposure to EPS624. The EPS624 polyelectrolyte coatings are cytocompatible, have immunoregulatory properties, and may be suitable for applications in biomedical engineering.

Lactobacillus casei-Derived Postbiotics Elevate the Bioaccessibility of Proteins via Allosteric Regulation of Pepsin and Trypsin and Introduction of Endopeptidases

The potential of probiotics to benefit digestion has been widely reported, while its utilization in high-risk patients and potential adverse reactions have focused interest on postbiotics. A variable data-independent acquisition (vDIA)-based spatial-omics strategy integrated with unsupervised variational autoencoders was applied to profile the functional mechanism underlying the action of Lactobacillus casei-derived postbiotic supplementation in goat milk digestion in an infant digestive system, from a metabolomics-peptidomics-proteomics perspective. Amide and olefin derivatives were proved to elevate the activities of pepsin and trypsin through hydrogen bonding and hydrophobic forces based on allosteric effects, and recognition of nine endopeptidases and their cleavage to serine, proline, and aspartate were introduced by postbiotics, thereby promoting the generation of hydrophilic peptides and elevating the bioaccessibility of goat milk protein. The peptides originating from αs1-casein, β-casein, β-lactoglobulin, Ig-like domain-containing protein, κ-casein, and serum amyloid A protein, with multiple bioactivities including angiotensin I-converting enzyme (ACE)-inhibitory, osteoanabolic, dipeptidyl peptidase IV (DPP-IV) inhibitory, antimicrobial, bradykinin-potentiating, antioxidant, and anti-inflammatory activities, were significantly increased in the postbiotic supplementation group, which was also considered to potentially prevent necrotizing enterocolitis through inhibiting the multiplication of pathogenic bacteria and blocking signal transducer and activator of transcription 1 and nuclear factor kappa-light-chain-enhancer of activated B cells inflammatory pathways. This research deepened the understanding of the mechanism underlying the postbiotics affecting goat milk digestion, which established a critical groundwork for the clinical application of postbiotics in infant complementary foods.

Nanoencapsulation of Docetaxel Induces Concurrent Apoptosis and Necroptosis in Human Oral Cancer Cells (SCC-9) via TNF-α/RIP1/RIP3 Pathway

Human oral squamous cell carcinoma is the sixth most frequent malignant cancer, with an unacceptably high death rate that affects people's health. Albeit, there are several clinical approaches for diagnosing and treating oral cancer they are still far from ideal. We previously synthesised and characterised the docetaxel nanoformulation (PLGA-Dtx) and discovered that docetaxel nanoencapsulation may suppress oral cancer cells. The goal of this study was to figure out the mechanism involved in the suppression of oral cancer cell proliferation. We discovered that PLGA-Dtx inhibited SCC-9 cell growth considerably as compared to free docetaxel (Dtx), and that the viability of SCC-9 cells treated with PLGA-Dtx was decreased dose-dependently. MTT assay showed that PLGA-Dtx selectively inhibited the growth of PBMCs from oral cancer patients while sparing PBMCs from normal healthy controls. Further, flow cytometry analysis showed that PLGA-Dtx induced apoptosis and necroptosis in SCC-9 cells. G2/M cell cycle arrest has been confirmed on exposure of PLGA-Dtx for 24 h in SCC-9 cells. Interestingly, western blot investigation found that PLGA-Dtx increased the amounts of necroptic proteins and apoptosis-related proteins more efficiently than Dtx. Furthermore, PLGA-Dtx was more effective in terms of ROS generation, and mitochondrial membrane potential depletion. Pretreatment with necroptosis inhibitor Nec-1 efficiently reversed the ROS production and further recover MMP caused by PLGA-Dtx. Overall, this study revealed a mechanistic model of therapeutic response for PLGA-Dtx in SCC-9 cells and proposed its potency by inducing cell death via activation of concurrent apoptosis and necroptosis in SCC-9 cells via TNF-α/RIP1/RIP3 and caspase-dependent pathway.

Zinc and selenium attenuate quaternary heavy metal mixture-induced testicular damage via amplification of the antioxidant system, reduction in metal accumulation, inflammatory and apoptotic biomarkers

Heavy metals (HMs) such as cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) are highly toxic elements. They are often found together in nature as a heavy metal mixture (HMM) and are known to contribute to subfertility/infertility as environmental pollutants. This study aims to evaluate the potential benefits of treating HMM-induced testicular pathophysiology with zinc (Zn) and/or selenium (Se). Six-week-old male Sprague Dawley rats were grouped into 5 (n = 7). The control group received deionized water, while the other groups were treated with PbCl2 (20 mg kg-1), CdCl2 (1.61 mg kg-1), HgCl2 (0.40 mg kg-1), and Na2AsO3 (10 mg kg-1) in deionized water for 60 days. Additionally, groups III to V received Zn, Se, and Zn/Se, respectively, for 60 days. The study evaluated testis weight, metal accumulation, sperm analysis, FSH, LH, testosterone, prolactin, oxidative stress, antioxidants, pro-inflammatory and apoptotic markers, and presented structural changes in the testis as micrographs. HMM caused a significant increase in testis weight, metal accumulation, prolactin, oxidative stress, and pro-inflammatory and apoptotic markers, while significantly decreasing semen analysis, FSH, LH, and testosterone. Histology showed decreased spermatogenesis and spermiogenesis, as evidenced by the structure of the germ cells and spermatids. However, Zn, Se, or both ameliorated and reversed some of the observed damages. This study provides further evidence for the mitigative potential of Zn, Se, or both in reversing the damage inflicted by HMM in the testis, and as a countermeasure towards improving HM-induced decrease in public health fecundity.

Graphical abstract

Oxidative stress and valvular endothelial cells in aortic valve calcification

Calcified aortic valve disease (CAVD) is a common cardiovascular disease in elderly individuals. Although it was previously considered a degenerative disease, it is, in fact, a progressive disease involving multiple mechanisms. Aortic valve endothelial cells, which cover the outermost layer of the aortic valve and are directly exposed to various pathogenic factors, play a significant role in the onset and progression of CAVD. Hemodynamic changes can directly damage the structure and function of valvular endothelial cells (VECs). This leads to inflammatory infiltration and oxidative stress, which promote the progression of CAVD. VECs can regulate the pathological differentiation of valvular interstitial cells (VICs) through NO and thus affect the process of CAVD. Under the influence of pathological factors, VECs can also be transformed into VICs through EndMT, and then the pathological differentiation of VICs eventually leads to the formation of calcification. This review discusses the role of VECs, especially the role of oxidative stress in VECs, in the process of aortic valve calcification.

New insight into the composition of extracellular traps released by macrophages exposed to different types of inducers

Neutrophil extracellular trap (NET) release plays a key role in many chronic disease settings, including atherosclerosis. They are critical to innate immune defence, but also contribute to disease by promoting thrombosis and inflammation. Macrophages are known to release extracellular traps or "METs", but their composition and role in pathological processes are less well defined. In this study, we examined MET release from human THP-1 macrophages exposed to model inflammatory and pathogenic stimuli, including tumour necrosis factor α (TNFα), hypochlorous acid (HOCl) and nigericin. In each case, there was release of DNA from the macrophages, as visualized by fluorescence microscopy with the cell impermeable DNA binding dye SYTOX green, consistent with MET formation. Proteomic analysis on METs released from macrophages exposed to TNFα and nigericin reveals that they are composed of linker and core histones, together with a range of cytosolic and mitochondrial proteins. These include proteins involved in DNA binding, stress responses, cytoskeletal organisation, metabolism, inflammation, anti-microbial activity, and calcium binding. Quinone oxidoreductase in particular, was highly abundant in all METs but has not been reported previously in NETs. Moreover, there was an absence of proteases in METs in contrast to NETs. Some of the MET histones, contained post-translational modifications, including acetylation and methylation of Lys but not citrullination of Arg. These data provide new insight into the potential implications of MET formation in vivo and their contributions to immune defence and pathology.

Bavachin and Corylifol A Improve Muscle Atrophy by Enhancing Mitochondria Quality Control in Type 2 Diabetic Mice

Type 2 diabetes reduces muscle mass and function. Chronic inflammation and mitochondrial dysfunction play critical roles in muscle atrophy pathogenesis. Here, we investigated the effects of bavachin and corylifol A from Psoralea corylifolia L. seeds on muscle atrophy in dexamethasone-treated mice and in db/db mice. Bavachin and corylifol A enhanced muscle strength and muscle mass in dexamethasone-treated mice. In diabetic mice, they enhanced muscle strength and cross-sectional areas. Bavachin and corylifol A suppressed inflammatory cytokine (interleukin-6 and tumor necrosis factor-α) expression levels by downregulating nuclear factor-κB phosphorylation. They decreased the muscle atrophic factor (myostatin, atrogin-1, and muscle RING finger-1) expression levels. They activated the AKT synthetic signaling pathway and induced a switch from fast-type glycolytic fibers (type 2B) to slow-type oxidative fibers (types I and 2A). They increased mitochondrial biogenesis and dynamic factor (optic atrophy-1, mitofusin-1/2, fission, mitochondrial 1, and dynamin 1-like) expression levels via the AMP-activated protein kinase-peroxisome proliferator-activated receptor gamma coactivator 1-alpha signaling pathway. They also improved mitochondrial quality by upregulating the mitophagy factor (p62, parkin, PTEN-induced kinase-1, and BCL2-interacting protein-3) expression levels. Therefore, bavachin and corylifol A exert potential therapeutic effects on muscle atrophy by suppressing inflammation and improving mitochondrial function.

Innate immunity and early liver inflammation

The innate system constitutes a first-line defence mechanism against pathogens. 80% of the blood supply entering the human liver arrives from the splanchnic circulation through the portal vein, so it is constantly exposed to immunologically active substances and pathogens from the gastrointestinal tract. Rapid neutralization of pathogens and toxins is an essential function of the liver, but so too is avoidance of harmful and unnecessary immune reactions. This delicate balance of reactivity and tolerance is orchestrated by a diverse repertoire of hepatic immune cells. In particular, the human liver is enriched in many innate immune cell subsets, including Kupffer cells (KCs), innate lymphoid cells (ILCs) like Natural Killer (NK) cells and ILC-like unconventional T cells - namely Natural Killer T cells (NKT), γδ T cells and Mucosal-associated Invariant T cells (MAIT). These cells reside in the liver in a memory-effector state, so they respond quickly to trigger appropriate responses. The contribution of aberrant innate immunity to inflammatory liver diseases is now being better understood. In particular, we are beginning to understand how specific innate immune subsets trigger chronic liver inflammation, which ultimately results in hepatic fibrosis. In this review, we consider the roles of specific innate immune cell subsets in early inflammation in human liver disease.

Gene Expression Profiling Elucidates Cellular Responses to NCX4040 in Human Ovarian Tumor Cells: Implications in the Mechanisms of Action of NCX4040

The nitric oxide donor, NCX4040 is a non-steroidal anti-inflammatory-NO donor and has been shown to be extremely cytotoxic to a number of human tumors, including ovarian tumors cells. We have found that NCX4040 is cytotoxic against both OVCAR-8 and its adriamycin-selected OVCAR-8 variant (NCI/ADR-RES) tumor cell lines. While the mechanism of action of NCX4040 is not entirely clear, we as well as others have shown that NCX4040 generates reactive oxygen species (ROS) and induces DNA damage in tumor cells. Recently, we have reported that NCX4040 treatment resulted in a significant depletion of cellular glutathione, and formation of both reactive oxygen and nitrogen species (ROS/RNS), resulting in oxidative stress in these tumor cells. Furthermore, our results indicated that more ROS/RNS were generated in OVCAR-8 cells than in NCI/ADR-RES cells due to increased activities of superoxide dismutase (SOD), glutathione peroxidase and transferases expressed in NCI/ADR-RES cells. Further studies suggested that NCX4040-induced cell death may be mediated by peroxynitrite formed from NCX4040 in cells. In this study we used microarray analysis following NCX4040 treatment of both OVCAR-8 and its ADR-resistant variant to identify various molecular pathways involved in NCX4040-induced cell death. Here, we report that NCX4040 treatment resulted in the differential induction of oxidative stress genes, inflammatory response genes (TNF, IL-1, IL-6 and COX2), DNA damage response and MAP kinase response genes. A mechanism of tumor cell death is proposed based on our findings where oxidative stress is induced by NCX4040 from simultaneous induction of NOX4, TNF-α and CHAC1 in tumor cell death.

The role of the canonical nf-κb signaling pathway in the development of acute liver failure

As a clinical emergency with a high mortality rate, the treatment of acute liver failure has been paid attention to by society. At present, liver transplantation is the most effective treatment for acute liver failure, but there is still an insufficient supply of liver sources and a poor prognosis. In view of the current therapeutic development of this disease, more researchers have turned their attention to the research of drugs related to the NF-κB pathway. The NF-κB canonical pathway has been proven to play a role in a variety of diseases, regulating inflammation, apoptosis, and other physiological processes. More and more evidence shows that the NF-κB canonical pathway regulates the pathogenesis of acute liver failure. In this review, we will summarize the regulation process of the NF-κB canonical pathway on acute liver failure, and develop a new way to treat acute liver failure by targeting the components of the pathway.

Roles of RIPK3 in necroptosis, cell signaling, and disease

Receptor-interacting protein kinase-3 (RIPK3, or RIP3) is an essential protein in the "programmed" and "regulated" cell death pathway called necroptosis. Necroptosis is activated by the death receptor ligands and pattern recognition receptors of the innate immune system, and the findings of many reports have suggested that necroptosis is highly significant in health and human disease. This significance is largely because necroptosis is distinguished from other modes of cell death, especially apoptosis, in that it is highly proinflammatory given that cell membrane integrity is lost, triggering the activation of the immune system and inflammation. Here, we discuss the roles of RIPK3 in cell signaling, along with its role in necroptosis and various pathways that trigger RIPK3 activation and cell death. Lastly, we consider pathological situations in which RIPK3/necroptosis may play a role.

Unprocessed wheat γ-gliadin reduces gluten accumulation associated with the endoplasmic reticulum stress and elevated cell death

Along with increasing demands for high yield, elite processing quality and improved nutrient value in wheat, concerns have emerged around the effects of gluten in wheat-based foods on human health. However, knowledge of the mechanisms regulating gluten accumulation remains largely unexplored. Here we report the identification and characterization of a wheat low gluten protein 1 (lgp1) mutant that shows extremely low levels of gliadins and glutenins. The lgp1 mutation in a single γ-gliadin gene causes defective signal peptide cleavage, resulting in the accumulation of an excessive amount of unprocessed γ-gliadin and a reduced level of gluten, which alters the endoplasmic reticulum (ER) structure, forms the autophagosome-like structures, leads to the delivery of seed storage proteins to the extracellular space and causes a reduction in starch biosynthesis. Physiologically, these effects trigger ER stress and cell death. This study unravels a unique mechanism that unprocessed γ-gliadin reduces gluten accumulation associated with ER stress and elevated cell death in wheat. Moreover, the reduced gluten level in the lgp1 mutant makes it a good candidate for specific diets for patients with diabetes or kidney diease.

Fucoidan, as an immunostimulator promotes M1 macrophage differentiation and enhances the chemotherapeutic sensitivity of capecitabine in colon cancer

Chemotherapy resistance is one of the most critical challenges in colorectal cancer (CRC) treatment. The occurrence and development of chemotherapy resistance closely related to the tumor immune microenvironment (TIME). As the most important immunosuppressive immune cells infiltrating into the TIME, macrophages are essential for chemotherapy resistance in CRC treatment. In this study, we found that a kind of fucoidan (FPS1M) induced macrophages differentiation to the M1 phenotype, and this transformation promoted cancer cells apoptosis both in vitro and in vivo. TNFα is a key mediator of FPS1M-induced tumorcidal activity of macrophages. Mechanistically, as a stimulator of TLR4, FPS1M enhanced macrophages glycolysis and regulated macrophages differentiation to the M1 phenotype by the activation of TLR4 mediated PI3K/AKT/mTOR signaling axis. In addition, FPS1M improved the immunosuppressed tumor microenvironment by increasing the infiltration of M1 macrophages in tumor tissue, which was conducive to improving the sensitivity of tumor to chemotherapy. Collectively, our findings demonstrated that FPS1M has the great potential to be used in tumor immunotherapy. The results also suggested that the combination of FPS1M with capecitabine is an alternative therapy method for colon cancer.

Role of oxidative stress-mediated cell death and signaling pathways in experimental fluorosis

Free radicals and other oxidants have enticed the interest of researchers in the fields of biology and medicine, owing to their role in several pathophysiological conditions, including fluorosis (Fluoride toxicity). Radical species affect cellular biomolecules such as nucleic acids, proteins, and lipids, resulting in oxidative stress. Reactive oxygen species-mediated oxidative stress is a common denominator in fluoride toxicity. Fluorosis is a global health concern caused by excessive fluoride consumption over time. Fluoride alters the cellular redox homeostasis, and its toxicity leads to the activation of cell death mechanisms like apoptosis, autophagy, and necroptosis. Even though a surfeit of signaling pathways is involved in fluorosis, their toxicity mechanisms are not fully understood. Thus, this review aims to understand the role of reactive species in fluoride toxicity with an outlook on the effects of fluoride in vitro and in vivo models. Also, we emphasized the signal transduction pathways and the mechanism of cell death implicated in fluoride-induced oxidative stress.

Cytokine storm: behind the scenes of the collateral circulation after acute myocardial infarction

At least 17 million people die from acute myocardial infarction (AMI) every year, ranking it first among causes of death of human beings, and its incidence is gradually increasing. Typical characteristics of AMI include acute onset and poor prognosis. At present, there is no satisfactory treatment, but development of coronary collateral circulation (CCC) can be key to improving prognosis. Recent research indicates that the levels of cytokines, including those related to promoting inflammatory responses and angiogenesis, increase after the onset of AMI. In the early phase of AMI, cytokines play a vital role in inducing development of collateral circulation. However, when myocardial infarction is decompensated, cytokine secretion increases greatly, which may induce a cytokine storm and worsen prognosis. Cytokines can regulate the activation of a variety of signal pathways and form a complex network, which may promote or inhibit the establishment of collateral circulation. We searched for published articles in PubMed and Google Scholar, employing the keyword “acute myocardial infarction”, “coronary collateral circulation” and “cytokine storm”, to clarify the relationship between AMI and a cytokine storm, and how a cytokine storm affects the growth of collateral circulation after AMI, so as to explore treatment methods based on cytokine agents or inhibitors used to improve prognosis of AMI.

Ethanolic Extract of Tridax procumbens Mitigates Pulmonary Inflammation via Inhibition of NF-κB/p65/ERK Mediated Signalling in an Allergic Asthma Model

BACKGROUND

Tridax procumbens is a traditionally used medicinal plant with high content of active phytoconstituents having anti-inflammatory activity. Accumulating evidences have shown that Tridax procumbens efficaciously diminished oxidative stress and inflammation. However the anti-inflammatory role of Tridax procumbens is not obscured in allergic asthma.

PURPOSE

Aim of this study was to decipher the anti-inflammatory role of Tridax procumbens in allergic asthma and its underlying mechanism.

METHODS

Ethanolic extract of Tridax procumbens (TP) was prepared and major phytoconstituents (flavonoids) were characterized by biochemical and UPLC/MS analysis. Rats were sensitized and challenged with environmental allergen ovalbumin (OVA) and lipopolysaccharide (LPS) to establish an allergic asthma model. Persuasive anti-inflammatory role of TP was demonstrated in vivo (100, 200 and 400 mg/kg) and in vitro (250, 125, 75 and 25 µg/ml) experiments.

RESULTS

Characterization by UPLC/MS analysis showed the presence of various bioactive flavonoids. In in vitro study, significant reduction in ROS production, apoptosis and mitochondrial dysfunction were observed in alveolar type II cells upon pre-treatment with TP (250, 125, 75 and 25 µg/ml) in a concentration-dependant manner. In vivo, TP (200 mg/kg) oral administration showed robust anti-oxidative activity. TP treatment abrogated bronchial wall thickening, immune cell infiltration and bronchial wall fibre deposition. Immunohistochemical analysis showed the diminished expression of IL-1β, IL-6 in bronchial epithelium and vascular endothelium. TP abrogated inflammation by reducing the level of inflammatory cytokines including IL-2, IFN-γ, IL-6 and MCP-1, as well as inflammatory markers including TWEAK, TNF-α, TNF-R1 and its downstream transcription factor NF-ҡB/p65 activation and its nuclear translocation. Western blot analysis of TP treated lung tissue and alveolar type II cells showed reduced phosphorylation of ERK1/2 significantly.

CONCLUSION

TP exhibited anti-inflammatory activity by inhibition of ROS production and down-regulation of NF-ҡB/ERK signalling in vitro and in vivo asthma model. Thus, TP can be envisaged as an effective anti-inflammatory agent for OVA-induced allergic asthma.

RIP3-Dependent Accumulation of Mitochondrial Superoxide Anions in TNF-α-Induced Necroptosis

Excessive production of reactive oxygen species (ROS) is a key phenomenon in tumor necrosis factor (TNF)-α-induced cell death. However, the role of ROS in necroptosis remains mostly elusive. In this study, we show that TNF-α induces the mitochondrial accumulation of superoxide anions, not H2O2, in cancer cells undergoing necroptosis. TNF-α-induced mitochondrial superoxide anions production is strictly RIP3 expression-dependent. Unexpectedly, TNF-α stimulates NADPH oxidase (NOX), not mitochondrial energy metabolism, to activate superoxide production in the RIP3-positive cancer cells. In parallel, mitochondrial superoxide-metabolizing enzymes, such as manganese-superoxide dismutase (SOD2) and peroxiredoxin III, are not involved in the superoxide accumulation. Mitochondrial-targeted superoxide scavengers and a NOX inhibitor eliminate the accumulated superoxide without affecting TNF-α-induced necroptosis. Therefore, our study provides the first evidence that mitochondrial superoxide accumulation is a consequence of necroptosis.

Potential Pathophysiological Mechanisms Underlying Multiple Organ Dysfunction in Cytokine Release Syndrome

In recent decades, many serious respiratory infections have broken out all over the world, including SARS-CoV, MERS, and COVID-19. They are characterized by strong infectivity, rapid disease progression, high mortality, and poor prognosis. Excessive immune system activation results in cytokine hypersecretion, which is an important reason for the aggravation of symptoms, and can spread throughout the body leading to systemic multiple organ dysfunction, namely, cytokine release syndrome (CRS). Although many diseases related to CRS have been identified, the mechanism of CRS is rarely mentioned clearly. This review is intended to clarify the pathogenetic mechanism of CRS in the deterioration of related diseases, describe the important signaling pathways and clinical pathophysiological characteristics of CRS, and provide ideas for further research and development of specific drugs for corresponding targets to treat CRS.

Reactive Oxygen Species Induced Pathways in Heart Failure Pathogenesis and Potential Therapeutic Strategies

With respect to structural and functional cardiac disorders, heart failure (HF) is divided into HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Oxidative stress contributes to the development of both HFrEF and HFpEF. Identification of a broad spectrum of reactive oxygen species (ROS)-induced pathways in preclinical models has provided new insights about the importance of ROS in HFrEF and HFpEF development. While current treatment strategies mostly concern neuroendocrine inhibition, recent data on ROS-induced metabolic pathways in cardiomyocytes may offer additional treatment strategies and targets for both of the HF forms. The purpose of this article is to summarize the results achieved in the fields of: (1) ROS importance in HFrEF and HFpEF pathophysiology, and (2) treatments for inhibiting ROS-induced pathways in HFrEF and HFpEF patients. ROS-producing pathways in cardiomyocytes, ROS-activated pathways in different HF forms, and treatment options to inhibit their action are also discussed.

Apiaceous vegetables protect against acrolein-induced pulmonary injuries through modulating hepatic detoxification and inflammation in C57BL/6 male mice

Acrolein (Acr) is a reactive aldehyde in the environment. Acr causes oxidative stress and a cascade of catalytic events and has, thereby, been associated with increased risk of pulmonary diseases. Whether apiaceous vegetables (API) consumption can prevent Acr-induced pulmonary toxicity has not yet been explored hence, we investigated the effects of API on Acr-induced pulmonary damages in C57BL/6J mice. The mice were assigned into either negative control [NEG group; American Institute of Nutrition (AIN)-93G diet only], positive control (POS group; AIN-93G+Acr) or API intervention group (API group; AIN-93G+21% API+Acr). After 1 week of dietary intervention, the POS and API mice were exposed to Acr (10 µmol/kg body weight/day) for 5 days. During the exposure period, assigned diets remained the same. Prominent indicators lung of toxicity of POS mice were found, including mucus accumulation, macrophage infiltration, and hemorrhage, all of which were ameliorated by the API. Serum and lung inflammation markers, such as a tumor necrosis factor alpha were also increased by Acr while reduced by API. In the liver, API upregulated expression of glutathione S-transferases, which enhanced the metabolism of Acr into water-soluble 3-hydroxypropyl mercapturic acid for excretion. This is consistent with observed reductions in serum Acr-protein adducts. Taken together, our results suggest that API may provide protection against Acr-induced pulmonary damages and inflammation via enhancement of the hepatic detoxification of Acr.

Aberrations in the Cross-Talks Among Redox, Nuclear Factor-κB, and Wnt/β-Catenin Pathway Signaling Underpin Myalgic Encephalomyelitis and Chronic Fatigue Syndrome

There is evidence that chronic fatigue spectrum disorders (CFAS-Ds), including myalgic encephalomyelitis (ME), chronic fatigue syndrome (CFS), and chronic fatigue with physiosomatic symptoms including when due to comorbid medical disease, are characterized by neuroimmune and neuro-oxidative biomarkers. This study was performed to delineate the protein-protein interaction (PPI) network of CFAS-D and to discover the pathways, molecular patterns, and domains enriched in their PPI network. We performed network, enrichment, and annotation analyses using differentially expressed proteins and metabolics, which were established in patients with CFAS-D. The PPI network analysis revealed that the backbone of the highly connective CFAS-D network comprises NFKB1, CTNNB1, ALB, peroxides, NOS2, tumor necrosis factor (TNF), and interleukin-6 (IL-6) and that the network comprises interconnected immune-oxidative-nitrosative and Wnt/β-catenin subnetworks. Multiomics enrichment analysis shows that the CFAS-D network is highly significantly associated with cellular (antioxidant) detoxification, hydrogen peroxide metabolic process, peroxidase and oxidoreductase activity, interleukin-10 (IL-10) anti-inflammatory signaling and neurodegenerative canonical Wnt, the β-catenin complex, cadherin domains, cell-cell junctions and TLR2/4 pathways, and the transcription factors nuclear factor kappa B (NF-κB) and RELA. The top 10 DOID annotations of the CFAS-D network include four intestinal, three immune system disorders, cancer, and infectious disease. The custom Gene Ontology (GO) term annotation analysis revealed that the CFAS-D network is associated with a response to a toxic substance, lipopolysaccharides, bacterium, or virus. In conclusion, CFAS-D may be triggered by a variety of stimuli and their effects are mediated by aberrations in the cross-talks between redox, NF-κB, and Wnt/β-catenin signaling pathways leading to dysfunctions in multicellular organismal homeostatic processes.

Natural Products as the Modulators of Oxidative Stress: An Herbal Approach in the Management of Prostate Cancer

Prostate cancer is the most commonly diagnosed and frequently occurred cancer in the males globally. The current treatment strategies available to treat prostate cancer are not much effective and express various adverse effects. Hence, there is an urgent need to identify novel treatment that can improve patient outcome. From times immemorial, natural products are highly recognized for novel drug development for various diseases including cancer. Cancer cells generally maintain higher basal levels of reactive oxygen species (ROS) when compared to normal cells due to its high metabolic rate. However, initiation of excess intracellular ROS production can not be tolerated by the cancer cells and induce several cell death signals which are in contrast to normal cells. Therefore, small molecules of natural origin that induce ROS can potentially kill cancer cells in specific and provide a better opportunity to develop a novel drug therapy. In this review, we elaborated various classes of medicinal compounds and their mechanism of killing prostate cancer cells through direct or indirect ROS generation. This can generate a novel thought to develop promising drug candidate to treat prostate cancer patients.

Astaxanthin Attenuates D-Galactosamine-Induced Pancreatic Injury by Activating Antioxidant Enzymes and Inhibiting VEGF-C Gene Expression

<b>Background and Objective:</b> Astaxanthin (3,3'-dihydroxy-β-β-carotene-4,4'-dione) is a carotenoid, commonly found in marine environments has been reported to possess versatile biological properties including anti-inflammatory and antioxidant. In this study, the pancreatic protective effect of astaxanthin was investigated in D-Galactosamine-induced pancreas injury in rats. <b>Materials and Methods:</b> In this experimental study, MTT assay was used to determine cytotoxic effects of the Astaxanthin on pnc1 cells. A total of 30 adult albino rats divided into 5 groups, six rats in each. Group I was given an equal amount of distilled water, group II was received 400 mg kg<sup>1</sup> b.wt. D-galactosamine on 15th day, groups III-V were treated with astaxanthin (50 and 100 mg kg<sup>1</sup>) and/or silymarin (50 mg kg<sup>1</sup>) for 14 days + 400 mg kg<sup>1</sup> b.wt. D-galactosamine on the 15th day, respectively. <b>Results:</b> IC<sub>50 </sub>of Astaxanthin against the pnc1 cell line was 92.9 μg mL<sup>1</sup>. The daily oral administration of astaxanthin (50 and 100 mg kg<sup>1</sup>) as well as silymarin (50 mg kg<sup>1</sup>) for 14 days to rats treated with D-galactosamine resulted in a significant improvement in plasma AST, ALT, ALP as well as pancreatic TNF-α, IL-1β, IL-10, NO and VEGF-C gene expression. On the other hand, inducible oral administration of astaxanthin increased the activity of pancreatic GSH, SOD, GPx, GR, CAT and the level of TBARs in D-galactosamine-treated pancreatic of rats. Furthermore, Astaxanthin almost normalized these effects in pancreatic tissue histoarchitecture and MRI examination. <b>Conclusion:</b> The obtained results showed that Astaxanthin protected experimental animals against D-galactosamine-induced pancreatic injury through activation of antioxidant enzymes and IL-10 and inhibition of VEGF-C activation.

Effect of roasted peanut allergen Ara h 3 protein on the sensitization of Caco-2 cells

BACKGROUND

Roasted peanut is widely loved as a kind of food with rich taste. However, peanut allergy is one of the major threats to human health, which affects about 5% of children and 1.4-2% of adults in the world.

RESULTS

To evaluate the sensitization mechanism of peanut allergen Ara h 3, Caco-2 cells as the model, which has the similar structure and function to differentiated small intestinal epithelial cells. Compared with Ara h 3-raw (purified from raw peanut) group, more significant results such as the inhibited Caco-2 cell viability and proliferation, the increased secretion of reactive oxygen species (ROS) and the decreased transepithelial electrical resistance were obtained in Ara h 3-roasted (purified from roasted peanut) group. Accordingly, oxidative stress and NF-κB signaling pathway were more imbalanced, which lead to the increased of thymic stromal lymphopoietin (TSLP), interleukin 6 (IL-6), IL-8 and monocyte chemotactic protein 1 (MCP-1). Then, the gene expression of tight junction proteins ZO-1, occludin and JAM-1 were reduced, which proved that the integrity of the Caco-2 monolayer barrier is severely damaged.

CONCLUSION

These finding identify the mechanisms of the allergenicity of roasted peanut allergy proteins are probably associated with intestinal uptake and cytokine dependent allergies. The aggravated allergic reaction might be caused by the increment of TSLP, IL-6, IL-8 and MCP-1 due to the activated NF-κB signaling pathway, and the enhanced transport of Ara h 3-roasted protein by Caco-2 monolayer. © 2021 Society of Chemical Industry.

The role of globins in cardiovascular physiology

Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system. The ability of each of these globins to interact with molecular oxygen (O₂) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extra-erythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in non-vascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the central and peripheral nervous systems. Brain and central nervous system neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and, thus, tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme-iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scaveging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology with a focus on NO biology, and offer perspectives for future study of these functions.

Redox Signaling and Sarcopenia: Searching for the Primary Suspect

Sarcopenia, the age-related decline in muscle mass and function, derives from multiple etiological mechanisms. Accumulative research suggests that reactive oxygen species (ROS) generation plays a critical role in the development of this pathophysiological disorder. In this communication, we review the various signaling pathways that control muscle metabolic and functional integrity such as protein turnover, cell death and regeneration, inflammation, organismic damage, and metabolic functions. Although no single pathway can be identified as the most crucial factor that causes sarcopenia, age-associated dysregulation of redox signaling appears to underlie many deteriorations at physiological, subcellular, and molecular levels. Furthermore, discord of mitochondrial homeostasis with aging affects most observed problems and requires our attention. The search for the primary suspect of the fundamental mechanism for sarcopenia will likely take more intense research for the secret of this health hazard to the elderly to be unlocked.

Immuno-modulatory effects of nanoplastics and humic acids in the European seabass (Dicentrarchus labrax)

Pernicious effects of plastic particles, emergent contaminants worldwide, have been described in different species. In teleost species, alterations of immune function after exposure to nanoplastics (NPs) have been reported, but the interaction with cortisol - hypothalamic-pituitary-adrenal (HPI) axis has not yet been explored. Furthermore, the role of dissolved organic matter on the effects of NPs is poorly known. Thus, the aims of this research were to assess if polystyrene NPs (PSNPs) acted as a stressor on juvenile European seabass (Dicentrarchus labrax), interfering with the immune response, as well as to elucidate if humic acids (HA) modulated the potential effects of PSNPs. A short-term exposure to PSNPs and HA elicited an immuno-modulatory response, with an activation of steroidogenic stress-related pathways. An upregulation of anti-inflammatory cytokine (il10, tgfb) and stress-related (mc2r, gr1) transcripts were observed after exposure to HA and PSNPs both individually and in co-exposure. No notable alteration of inflammatory markers was consistently found, which may reflect a protective anti-inflammatory effect of HA in the presence of PSNPs. Nevertheless, there seems to be a more complex interaction between both components. Overall, data show that understanding the interaction of NPs with dissolved organic substances is key to deciphering their environmental risks.

The Role of Nutrition in COVID-19 Susceptibility and Severity of Disease: A Systematic Review

BACKGROUND

Many nutrients have powerful immunomodulatory actions with the potential to alter susceptibility to coronavirus disease 2019 (COVID-19) infection, progression to symptoms, likelihood of severe disease, and survival.

OBJECTIVE

The aim was to review the latest evidence on how malnutrition across all its forms (under- and overnutrition and micronutrient status) may influence both susceptibility to, and progression of, COVID-19.

METHODS

We synthesized information on 13 nutrition-related components and their potential interactions with COVID-19: overweight, obesity, and diabetes; protein-energy malnutrition; anemia; vitamins A, C, D, and E; PUFAs; iron; selenium; zinc; antioxidants; and nutritional support. For each section we provide: 1) a landscape review of pertinent material; 2) a systematic search of the literature in PubMed and EMBASE databases, including a wide range of preprint servers; and 3) a screen of 6 clinical trial registries. All original research was considered, without restriction to study design, and included if it covered: 1) severe acute respiratory syndrome coronavirus (CoV) 2 (SARS-CoV-2), Middle East respiratory syndrome CoV (MERS-CoV), or SARS-CoV viruses and 2) disease susceptibility or 3) disease progression, and 4) the nutritional component of interest. Searches took place between 16 May and 11 August 2020.

RESULTS

Across the 13 searches, 2732 articles from PubMed and EMBASE, 4164 articles from the preprint servers, and 433 trials were returned. In the final narrative synthesis, we include 22 published articles, 38 preprint articles, and 79 trials.

CONCLUSIONS

Currently there is limited evidence that high-dose supplements of micronutrients will either prevent severe disease or speed up recovery. However, results of clinical trials are eagerly awaited. Given the known impacts of all forms of malnutrition on the immune system, public health strategies to reduce micronutrient deficiencies and undernutrition remain of critical importance. Furthermore, there is strong evidence that prevention of obesity and type 2 diabetes will reduce the risk of serious COVID-19 outcomes. This review is registered at PROSPERO as CRD42020186194.

From Flies to Men: ROS and the NADPH Oxidase in Phagocytes

The cellular formation of reactive oxygen species (ROS) represents an evolutionary ancient antimicrobial defense system against microorganisms. The NADPH oxidases (NOX), which are predominantly localized to endosomes, and the electron transport chain in mitochondria are the major sources of ROS. Like any powerful immunological process, ROS formation has costs, in particular collateral tissue damage of the host. Moreover, microorganisms have developed defense mechanisms against ROS, an example for an arms race between species. Thus, although NOX orthologs have been identified in organisms as diverse as plants, fruit flies, rodents, and humans, ROS functions have developed and diversified to affect a multitude of cellular properties, i.e., far beyond direct antimicrobial activity. Here, we focus on the development of NOX in phagocytic cells, where the so-called respiratory burst in phagolysosomes contributes to the elimination of ingested microorganisms. Yet, NOX participates in cellular signaling in a cell-intrinsic and -extrinsic manner, e.g., via the release of ROS into the extracellular space. Accordingly, in humans, the inherited deficiency of NOX components is characterized by infections with bacteria and fungi and a seemingly independently dysregulated inflammatory response. Since ROS have both antimicrobial and immunomodulatory properties, their tight regulation in space and time is required for an efficient and well-balanced immune response, which allows for the reestablishment of tissue homeostasis. In addition, distinct NOX homologs expressed by non-phagocytic cells and mitochondrial ROS are interlinked with phagocytic NOX functions and thus affect the overall redox state of the tissue and the cellular activity in a complex fashion. Overall, the systematic and comparative analysis of cellular ROS functions in organisms of lower complexity provides clues for understanding the contribution of ROS and ROS deficiency to human health and disease.

Effect of Pentoxifylline on Apoptotic-Related Gene Expression Profile, Learning and Memory Impairment Induced by Systemic Lipopolysaccharide Administration in the Rat Hippocampus

Background:

Inflammation is one of the effective factors, in the development of functional disorders of the nervous system. Pentoxifylline (PTX) has an inhibitory effect on inflammatory factors. Therefore the aim of this study was to evaluate the effect of PTX on learning, memory and expression of genes, involved in neuronal survival in the rat hippocampus, following systemic lipopolysaccharide (LPS) injection.

Methods:

Male rats were randomly divided into 5 groups of control, LPS and LPS + PTX, receiving doses of 10, 25 and 50 mg/kg of PTX, respectively. In LPS groups, LPS was injected (5 mg/kg; intraperitoneal), and after one week, rats received intraperitoneal PTX for 14 days, in the treatment groups. Learning and memory were evaluated by object location task (OLT) and novel object recognition (NOR). Then, the hippocampus was dissected in order to measure the expression of the associated genes.

Results:

The results showed that peripheral LPS injection caused significant damage (P < 0.01) to learning and memory with respect to controls, but PTX with doses of 10 and 50 mg/kg prevented these impairments. Results from reverse transcription polymerase chain reaction (RT-PCR) showed that LPS significantly increased the expression of Bax and TNF- α with respect to controls. PTX in the LPS + PTX group significantly increased the expression of Bcl-2, BAD and Caspase-3.

Conclusions:

Other than the increased Bcl-2 expression, PTX had no significant effect on the expression of other genes, therefore further studies are needed to find out how PTX improves the learning and memory impairments, following the peripheral inflammation.

Reactive oxygen species mediate TNF-α-induced inflammatory response in bone marrow mesenchymal cells

Objectives

It is generally believed that the inflammatory response in bone marrow mesenchymal stem cells (BMSCs) transplantation leads to poor survival and unsatisfactory effects, and is mainly mediated by cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α). In this study, we explored the mechanisms underlying the TNF-α-induced inflammatory response in BMSCs.

Materials and Methods

We treated BMSCs with TNF-α (1 and 10 ng/ml) for 5 days. The expression levels of key inflammatory mediators were evaluated by Real-time PCR. Intracellular ROS level was measured by using a 2, 7-dichlorofluorescein diacetate (DCF-DA).

Results

We found that TNF-α treatment dramatically increased the expression levels of some key inflammatory mediators, including IL-6, IL-1β, IFN-γ and transforming growth factor β (TGF-β). Moreover, TNF-α induced intracellular oxidative stress by elevating intracellular reactive oxygen species (ROS) level, which is due to the increase of lipid peroxidation, the reduction of antioxidant Glutathione (GSH) levels and the inhibition of many antioxidant enzyme activities in BMSCs. Interestingly, 5 µM curcumin, a ROS scavenger, dramatically lowered the TNF-α-induced inflammatory response in BMSCs. In addition, TNF-α induced the activation of extracellular-signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), p38 and their down-stream transcription factors nuclear factor kappa B (NF-κB) pathway.

Conclusion

ROS mediated the TNF-α-induced inflammatory response via MAPK and NF-κB pathway, and may provide a novel strategy to prevent the inflammatory-dependent impairments in BMSCs.

Protective effect of pyrrolidine dithiocarbamate on isoniazid/rifampicin‑induced liver injury in rats

Isoniazid (INH) and rifampicin (RIF) continue to be first line anti‑tuberculosis (TB) drugs. However, the use of these drugs is associated with hepatotoxicity. Nuclear factor‑κB (NF‑κB) plays a crucial role in regulating immunity and inflammation. It has been reported that pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF‑κB, exerts a hepatoprotective effect on acute and chronic liver damage. The aim of the present study was to explore the INH/RIF‑induced protective effects and mechanisms of PDTC on liver injury. Rats were intragastrically administered INH (50 mg/kg/day) and RIF (50 mg/kg/day) daily for 28 days. PDTC (50 mg/kg/day) was intraperitoneally injected 2 h after the co‑administration of INH and RIF to compare liver biochemical indicators in the serum, histopathological damage, NF‑κB activity, oxidative stress, hepatic mRNA expression of tumor necrosis factor (TNF)‑α, bile salt export pump (BSEP), and protein expression of BSEP. It was found that the inhibition of NF‑κB activation by PDTC treatment markedly alleviated liver biochemical and histological injury, decreased oxidative stress and mRNA levels of TNF‑α, and prevented decreases in BSEP mRNA and protein expression induced by the co‑administration of INH and RIF. Collectively, the present data suggested that INH/RIF‑induced liver injury is dependent on the activation of NF‑κB. PDTC exerted a therapeutic effect on INH/RIF‑induced liver injury by increasing BSEP expression, and exhibiting antioxidant and anti‑inflammatory activities.

Thiol-Redox Regulation in Lung Development and Vascular Remodeling

Significance: Redox homeostasis is finely tuned and governed by distinct intracellular mechanisms. The dysregulation of this either by external or internal events is a fundamental pathophysiologic base for many pulmonary diseases. Recent Advances: Based on recent discoveries, it is increasingly clear that cellular redox state and oxidation of signaling molecules are critical modulators of lung disease and represent a final common pathway that leads to poor respiratory outcomes. Critical Issues: Based on the wide variety of stimuli that alter specific redox signaling pathways, improved understanding of the disease and patient-specific alterations are needed for the development of therapeutic targets. Further Directions: For the full comprehension of redox signaling in pulmonary disease, it is essential to recognize the role of reactive oxygen intermediates in modulating biological responses. This review summarizes current knowledge of redox signaling in pulmonary development and pulmonary vascular disease.

Oxidative stress and related gene expression effects of cyfluthrin in human neuroblastoma SH-SY5Y cells: Protective effect of melatonin

This study was designed to assess oxidative stress induction in human neuroblastoma SH-SY5Y cells in response to cyfluthrin exposure. Cell viability MTT assay was carried out to assess cyfluthrin cytotoxicity; IC₃₀ and IC₅₀ values for cyfluthrin were calculated to be 4.81 ± 0.92 μM and 19.39 ± 3.44 μM, respectively. Cyfluthrin induced a significant increase in ROS generation, lipid peroxides measured as malondialdehyde (MDA) and nitric oxide (NO) production and a significant decrease in NQO1 activity. The antioxidant activity of melatonin (MEL), Trolox, N-acetylcysteine (NAC) and Sylibin against cyfluthrin-induced oxidative stress was examined. Cyfluthrin increased significantly gene expressions of apoptosis, proinflammation and oxidative stress (Bax, Bcl-2, Casp-3, BNIP3, AKT1, p53, APAF1, NFκB1, TNFα and Nrf2) mediators. In the most genes, the mRNA levels induced by cyfluthrin were partially reduced by MEL (1 μM). Cyfluthrin effects on gene expression profiling of oxidative stress pathway by Real-Time PCR array analysis showed that of the 84 genes examined, (fold change > 1.5) changes in mRNA levels were detected in 31 genes: 13 upregulated and 18 down-regulated. A fold change >3.0 fold was observed on upregulated CYBB, DUOX1, DUOX2, AOX1, BNIP3, HSPA1A, NOS2, and NQO1 genes. The greater fold change reversion (2.5 fold) by MEL (1 μM) was observed on cyfluthrin-upregulated CYBB, AOX1, BNIP3 and NOS2 genes. These results demonstrated that oxidative stress is a key element in cyfluthrin induced neurotoxicity as well as MEL may play a role in reducing cyfluthrin-induced oxidative stress.

Mitogen-Activated Protein Kinases (MAPKs) and Cholangiocarcinoma: The Missing Link

In recent years, the incidence of both liver and biliary tract cancer has increased. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the two most common types of hepatic malignancies. Whereas HCC is the fifth most common malignant tumor in Western countries, the prevalence of CCA has taken an alarming increase from 0.3 to 2.1 cases per 100,000 people. The lack of specific biomarkers makes diagnosis very difficult in the early stages of this fatal cancer. Thus, the prognosis of CCA is dismal and surgery is the only effective treatment, whilst recurrence after resection is common. Even though chemotherapy and radiotherapy may prolong survival in patients with CCA, the 5-year survival rate is still very low—a significant global problem in clinical diagnosis and therapy. The mitogen-activated protein kinase (MAPK) pathway plays an important role in signal transduction by converting extracellular stimuli into a wide range of cellular responses including inflammatory response, stress response, differentiation, survival, and tumorigenesis. Dysregulation of the MAPK cascade involves key signaling components and phosphorylation events that play an important role in tumorigenesis. In this review, we discuss the pathophysiological role of MAPK, current therapeutic options, and the current situation of MAPK-targeted therapies in CCA.

MLKL mediates apoptosis via a mutual regulation with PERK/eIF2α pathway in response to reactive oxygen species generation

The pseudokinase mixed lineage kinase domain-like protein (MLKL) is a core effector of necroptosis, and its function in necroptosis is widely studied. However, the function of MLKL in apoptosis remains unclear. In the present study, the role of MLKL in chelerythrine (CHE)-promoted apoptosis was studied. A special band of MLKL (i.e., *MLKL) was observed after treatment with CHE. MLKL and *MLKL were accumulated in the nucleus upon treatment with CHE and MLKL silencing reversed the CHE-induced apoptosis. Blockade of CHE-triggered reactive oxygen species (ROS) generation or inhibition of CHE-activated protein kinase-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2 α subunit (eIF2α) pathway reversed the apoptosis. A decreased ROS level inhibited CHE-mediated nuclear translocation of MLKL and *MLKL and the activation of eIF2α, whereas MLKL or eIF2α silencing did not affect the CHE-triggered ROS generation. Furthermore, MLKL silencing prevented the CHE-activated eIF2α signal, and eIF2α silencing blocked the CHE-induced nuclear translocation of MLKL and *MLKL. Our studies suggested that CHE possibly induces apoptosis through the nuclear translocation of MLKL and *MLKL, which is promoted by a mutual regulation between MLKL and PERK-eIF2α pathway in response to ROS formation. The present study clarified the new function of MLKL in apoptosis.

[The renin-angiotensin-aldosterone system as a potential target for therapy in patients with calcific aortic stenosis: a literature review]

Calcific aortic valve stenosis (CAVS) is a serious socio-economic problem in developed countries because this disease is the most common indication for aortic valve replacement. Currently, there are no methods for non-invasive treatment of CAVS. Nevertheless, it is assumed that effective drug therapy for CAVS can be developed on the basis of modulators of the renin-angiotensin-aldosterone system (RAAS), which is involved in the pathogenesis of this disease. The purpose of this paper is to compile and analyze current information on the role of RAAS in the CAVS pathophysiology. Recent data on the effectiveness of RAAS inhibition are reviewed.

Radiocontrast Agent Diatrizoic Acid Induces Mitophagy and Oxidative Stress via Calcium Dysregulation

Contrast-induced acute kidney injury (CI-AKI) is the third most common cause of hospital associated kidney damage. Potential mechanisms of CI-AKI may involve diminished renal hemodynamics, inflammatory responses, and direct cytotoxicity. The hypothesis for this study is that diatrizoic acid (DA) induces direct cytotoxicity to human proximal tubule (HK-2) cells via calcium dysregulation, mitochondrial dysfunction, and oxidative stress. HK-2 cells were exposed to 0–30 mg I/mL DA or vehicle for 2–24 h. Conversion of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and trypan blue exclusion indicated a decrease in mitochondrial and cell viability within 2 and 24 h, respectively. Mitochondrial dysfunction was apparent within 8 h post exposure to 15 mg I/mL DA as shown by Seahorse XF cell mito and Glycolysis Stress tests. Mitophagy was increased at 8 h by 15 mg I/mL DA as confirmed by elevated LC3BII/I expression ratio. HK-2 cells pretreated with calcium level modulators BAPTA-AM, EGTA, or 2-aminophenyl borinate abrogated DA-induced mitochondrial damage. DA increased oxidative stress biomarkers of protein carbonylation and 4-hydroxynonenol (4HNE) adduct formation. Caspase 3 and 12 activation was induced by DA compared to vehicle at 24 h. These studies indicate that clinically relevant concentrations of DA impair HK-2 cells by dysregulating calcium, inducing mitochondrial turnover and oxidative stress, and activating apoptosis.

Protective effects of Clematichinenoside AR against inflammation and cytotoxicity induced by human tumor necrosis factor-α

Clematichinenoside AR (AR), a major active ingredient extracted from traditional Chinese herb Clematis chinensis Osbeck, has been demonstrated to possess anti-inflammatory and immune-modulatory activities in the treatment of experimental rheumatoid arthritis (RA). The therapeutic potential of AR was supposed to be closely correlated to its ability against tumor necrosis factor-α (TNF-α). Therefore, we aimed to explore the protective effects of Clematichinenoside AR against inflammation and cytotoxicity induced by human TNF-α. AR treatment significantly decreased IL-6 and IL-8 secretion, and attenuated MMP-1 production in human RA-derived fibroblast-like synoviocyte MH7A cells stimulated by recombinant human TNF-α (rhTNF-α). AR might antagonize rhTNF-α-induced responses in MH7A cells through inhibiting p38 and ERK MAPKs signal activation. In TNF-α-sensitive murine fibroblast L929 cells, AR treatment attenuated the proliferation inhibition ratio induced by rhTNF-α/ActD and antagonized rhTNF-α-induced cytotoxicity. The cellular and nuclear morphological alterations in apoptotic characteristics induced by rhTNF-α/ActD in L929 cells were observed to be attenuated by the pretreatment with AR under a phase-contrast and fluorescence microscopy, respectively. The Annexin V-FITC/PI double-staining assay was performed to confirm that AR pretreatment obviously decreased the cell death. The antagonistic effects of AR against rhTNF-α-induced cytotoxicity might be potentially attributed to the degeneration of reactive oxygen species and the increasing of mitochondrial membrane potential, along with the suppression of durative phosphorylation of c-Jun N-terminal kinase (JNK). Collectively, our results indicated that AR antagonizes the inflammatory and cytotoxic activities induced by human TNF-α effectively in vitro, which provided further evidence for a novel mechanism underlying AR for treating RA correlating with excessive TNF-α production.

GKN2 promotes oxidative stress-induced gastric cancer cell apoptosis via the Hsc70 pathway

BACKGROUND

The GKN2 is a secretory protein, whose levels decrease in gastric cancer. The present study aimed to investigate the expression, function and mechanism of action of GKN2 in gastric cancer.

METHODS

Molecular biology assays were performed to elucidate the function and underlying mechanisms of GKN2 in gastric cancer under stress-induced condition in vivo and in vitro. Clinical specimens were used to assess the correlation of GKN2 and prognosis.

RESULTS

We found that overexpression of GKN2 significantly enhanced apoptosis and growth arrest in vitro. GKN2 expression increased in gastric cancer cells exposed to hydrogen peroxide and promoted reactive oxygen species-induced mitochondrial dysfunction and resulted in increased cell apoptosis via inhibition of NF-κB signaling pathway and activation of JNK signaling pathway through the direct interaction of GKN2 with Hsc70. Trefoil factor 1 might contribute to the tumor suppressing effects of GKN2. MiR-216a downregulated GKN2 expression. GKN2 also inhibited xenograft tumor growth and was an independent and significant prognostic factor for patients with gastric cancer treated with oxaliplatin.

CONCLUSIONS

Taken together, our data indicate that GKN2 may increase sensitivity of GC cells to the drugs which increase ROS levels in tumors. Inhibition of the interaction between GKN2 and Hsc70 could attenuate the effects induced by GKN2. GKN2 overexpression could be used to determine the subgroup of patients to obtain the more favorable outcome of oxaliplatin treatment and may be used as biomarker of the prognosis of this cancer.

α-Tocopherol Protects the Heart, Muscles, and Testes from Lipid Peroxidation in Growing Male Rats Subjected to Physical Efforts

The effect of α-tocopherol supplementation on adaptation to training is still equivocal. The aim of the study was to determine the effect of training and α-tocopherol supplementation on α-tocopherol and thiobarbituric acid reactive substance (TBARS) concentration in the rat liver, heart, muscles, and testes. Male Wistar rats (n = 32) were divided into four groups (nonsupplemented, not trained—C; nonsupplemented, trained—CT; supplemented, not trained—E; supplemented and trained—ET). During the 14-day experimental period, 2 mg/d of vitamin E as α-tocopherol acetate was administered to the animals (groups E and ET). Rats in the training group (CT and ET) were subjected to 15 minutes of treadmill running each day. The α-tocopherol levels in rat tissues were assessed using high-performance liquid chromatography (HPLC). Lipid peroxides were determined by TBARS spectrophotometric method. α-Tocopherol had a significant impact on α-tocopherol concentration in all tissues. Training increased the α-tocopherol concentration in the heart and muscles but reduced it in the liver. Training also caused increased lipid peroxidation in the muscles, heart, and testes; but a higher α-tocopherol content in tissues reduced the TBARS level. The main finding of the study is that impaired α-tocopherol status and its adequate intake is needed to maintain optimal status to prevent damage to the skeletal and cardiac muscles as well as the testes in growing individuals.

Development of calcific aortic valve disease: Do we know enough for new clinical trials?

Calcific aortic valve disease (CAVD), previously thought to represent a passive degeneration of the valvular extracellular matrix (VECM), is now regarded as an intricate multistage disorder with sequential yet intertangled and interacting underlying processes. Endothelial dysfunction and injury, initiated by disturbed blood flow and metabolic disorders, lead to the deposition of low-density lipoprotein cholesterol in the VECM further provoking macrophage infiltration, oxidative stress, and release of pro-inflammatory cytokines. Such changes in the valvular homeostasis induce differentiation of normally quiescent valvular interstitial cells (VICs) into synthetically active myofibroblasts producing excessive quantities of the VECM and proteins responsible for its remodeling. As a result of constantly ongoing degradation and re-deposition, VECM becomes disorganised and rigid, additionally potentiating myofibroblastic differentiation of VICs and worsening adaptation of the valve to the blood flow. Moreover, disrupted and excessively vascularised VECM is susceptible to the dystrophic calcification caused by calcium and phosphate precipitating on damaged collagen fibers and concurrently accompanied by osteogenic differentiation of VICs. Being combined, passive calcification and biomineralisation synergistically induce ossification of the aortic valve ultimately resulting in its mechanical incompetence requiring surgical replacement. Unfortunately, multiple attempts have failed to find an efficient conservative treatment of CAVD; however, therapeutic regimens and clinical settings have also been far from the optimal. In this review, we focused on interactions and transitions between aforementioned mechanisms demarcating ascending stages of CAVD, suggesting a predisposing condition (bicuspid aortic valve) and drug combination (lipid-lowering drugs combined with angiotensin II antagonists and cytokine inhibitors) for the further testing in both preclinical and clinical trials.

Involvement of TNF-α and IFN-γ in Inflammation-Mediated Cochlear Injury

Objectives:

Inflammation is crucial for the pathogenesis of acquired sensorineural hearing loss, but the precise mechanism involved remains elusive. Among a number of inflammatory mediators, tumor necrosis factor-alpha (TNF-α) plays a pivotal role in cisplatin ototoxicity. However, TNF-α alone is cytotoxic to cochlear sensory cells only at the extremely high concentrations, suggesting the involvement of other factors that may sensitize cells to TNF-α cytotoxicity. Since interferon gamma (IFN-γ) importantly contributes to the cochlear inflammatory processes, we aim to determine whether and how IFN-γ affects TNF-α cytotoxicity to cochlear sensory cells.

Methods:

TNF-α expression was determined with western blotting in RSL cells and immunolabeling of mouse temporal bone sections. HEI-OC1 cell viability was determined with MTT assays, cytotoxicity assays, and cytometric analysis with methylene blue staining. Cochlear sensory cell injury was determined in the organotypic culture of the mouse organ of Corti.

Results:

Spiral ligament fibrocytes were shown to upregulate TNF-α in response to pro-inflammatory stimulants. We demonstrated IFN-γ increases the susceptibility of HEI-OC1 cells to TNF-α cytotoxicity via JAK1/2-STAT1 signaling. TNFR1-mediated Caspase-1 activation was found to mediate the sensitization effect of IFN-γ on TNF-α cytotoxicity. The combination of IFN-γ and TNF-α appeared to augment cisplatin cytotoxicity to cochlear sensory cells ex vivo.

Conclusions:

Taken together, these findings suggest the involvement of IFN-γ in the sensitization of cochlear cells to TNF-α cytotoxicity, which would enable us to better understand the complex mechanisms underlying inflammation-mediated cochlear injury.

Mitochondrial electron transport chain, ROS generation and uncoupling (Review)

The mammalian mitochondrial electron transport chain (ETC) includes complexes I-IV, as well as the electron transporters ubiquinone and cytochrome c. There are two electron transport pathways in the ETC: Complex I/III/IV, with NADH as the substrate and complex II/III/IV, with succinic acid as the substrate. The electron flow is coupled with the generation of a proton gradient across the inner membrane and the energy accumulated in the proton gradient is used by complex V (ATP synthase) to produce ATP. The first part of this review briefly introduces the structure and function of complexes I-IV and ATP synthase, including the specific electron transfer process in each complex. Some electrons are directly transferred to O₂ to generate reactive oxygen species (ROS) in the ETC. The second part of this review discusses the sites of ROS generation in each ETC complex, including sites I_F and I_Q in complex I, site II_F in complex II and site III_Qo in complex III, and the physiological and pathological regulation of ROS. As signaling molecules, ROS play an important role in cell proliferation, hypoxia adaptation and cell fate determination, but excessive ROS can cause irreversible cell damage and even cell death. The occurrence and development of a number of diseases are closely related to ROS overproduction. Finally, proton leak and uncoupling proteins (UCP_S) are discussed. Proton leak consists of basal proton leak and induced proton leak. Induced proton leak is precisely regulated and induced by UCPs. A total of five UCPs (UCP1-5) have been identified in mammalian cells. UCP1 mainly plays a role in the maintenance of body temperature in a cold environment through non-shivering thermogenesis. The core role of UCP2-5 is to reduce oxidative stress under certain conditions, therefore exerting cytoprotective effects. All diseases involving oxidative stress are associated with UCPs.